When the Lord Jesus told the unbelieving people of His day that no sign should be given them save the sign of the Prophet Jonah, He was introducing that which for the rest of the age should be the one ultimate basis of relationship to Himself both as to faith and experience. In fact, He was setting forth that which changed the character of the dispensation and marked the passing from one age to another. This "sign" we know to be the Death and Resurrection of the Lord Jesus. That which it signified was and is that He is the Son of God.